FOAM CHAMBER a discharge device is designed to apply an expanded foam blanket over the surface of a flammable liquid fire as gently as possible to achieve extinguishment and/or vapor suppression. Foam chambers are suitable for the protection of fixed roof-mounted tanks and are to be used as low-expansion Type II discharge devices (as defined by NFPA11). A deflector is located inside the tank shell to deflect the discharge against the shell which results in a relatively gentle foam application on the fuel surface.